THUMB CMC JOINT ARTHRODESIS- EVOLUTION OF A SAFE AND EFFECTIVE TECHNIQUE

Abstract

Purpose: To evaluate retrospectively the functional and radiographic outcome of patients who had a thumb trapeziometacarpal (TM) joint arthrodesis using a T-plate, chevron bone cuts and autologous punch graft harvested from ipsilateral distal radius.

Material and Methods: Between 2001 and 2006, 32 trapeziometacarpal (TM) joint fusions were performed in 24 patients using the above technique. The study group comprised of 16 females and 8 males with average age 52 years (range 42–62 years). Average follow-up was 14.8 months (range 14–60 months). Indications for surgery were: failure of conservative treatment; severe pain; and diminished thumb function hampering everyday life. All patients had radiological evidence of advanced TM joint arthritis (Eaton and Littler grade II to III).

In all cases, chevron bone cuts have been used. The fixation has progressed from K-wires, through single and double lag screws, tension-band wire, to an AO mini T-plate which is the present technique. With the K-wire, or simple screw methods, the failure rates were up to 50%, leading to many revision operations. Bone graft is used; in first 15 cases this was ‘Allomatrix’ but we now use local bone from the distal radius, taken with an AO tap guide used as a trephine.

Functional outcomes were assessed using Quick DASH score, and Gartland and Werley score. There was also a radiographic review. The grip and pinch strength were compared with the contralateral side. We also looked at the progression of disease at scaphotrapezial joint after the fusion of TM joint.

Results: Patient-rated outcome scores indicated very good pain relief with preservation of grip and pinch strength. There were 2 cases (7%) of non-union which required revision surgery and were probably due to poor screw placement in the trapezium. In 8 patients (25%), pain related to prominent metalwork required plate removal. In no case was there x-ray or symptomatic progression of the disease at scaphotrapezial joint. Clinically, 75% rated good, 15% fair, and 10% poor results.

Conclusion: The present form of trapeziometacarpal arthrodesis is reproducible and offers an excellent alternative to trapeziectomy especially in younger patients.

Type of study/level of evidence: Therapeutic IV.